Sheet metal press



Oct. 22. 1935. I J RQDE ET AL 2,018,576

SH EET METAL PRES S Filed Dec. 14, 1934 2 Sheets-Sheet l Oct. 1935. J RQDE r AL 2,018,576

SHEET METAL PRESS Filed Dec. 14, 1934 2 Sheets-Sheet 2 Patented Oct. 22, 1935 UNITED STATES SHEET METAL PRESS Fredrich J. Rode and Meredith R. Hatch, Toledo, Ohio Application December 14, 1934, Serial No. 757,418

9 Claims.

Our invention relates to a sheet metal press .having a plurality of reciprocable plungers slidably disposed in a frame and adapted to engage and shape sheet metal in accordance with dies carried by the plungers. The invention particularly relates to a sheet metal press having reciprocable plungers some of which move in op.- posed directions to others to engage sheet metal, those of the plungers movable in one direction to operate on the sheet metal being driven by a machine drive shaft, and those plungers movable in the opposite direction being driven by a second and independent machine drive shaft, each machine drive shaft being operatively connected to an independent source of power.

The invention has for an object to provide a means for controlling the operation of each machine drive shaft whereby a desired synchrony of movement of the plungers connected thereto may be obtained, such as related descending and ascending strokes and periodic dwells of plungers in proper and useful sequence. The invention has for a further object to provide a means which may be manually, but which upon setting will function automatically to control the movement of the plungers of the press eliminating much of heretofore necessary supervision and attention of the press operator. This is of importance when the press being operated is of massive weight and the sheet metal being worked on of a material dimension.

The invention provides a triple action press which may be quickly and easily modified to perform a double action function in a common direction with reference to the work without the heretofore necessary unlinkage of various parts. In a press capable of performing tonnage work, the linkage is of a considerable bulkiness and weight, and interchangingfrom triple action to double action often involves much expense. In the press of our invention, the change-over may be efiected instantly by the operator.

The invention further provides a means whereby sheet metal presses of the double action type having a pair of nested plungers, one usually performing a blank holding duty, the other a sheet forming duty, may be modified by the addition of a third plunger acting in opposed direction to the blank holder to embody the features and advantages of a triple action sheet metal press with but little additional outlay and expense. The control means of our invention effects an interrelation and dependency as between the movements of the blank holder and associated plunger and the third plunger without intervention of other means.

The invention has for a particular object to provide in a sheet metal press having multiple plungers, each of which are driven by a driving means operably and independently connectible to a source of power, a means operable on the predetermined movement of some of the plungers for connecting or disconnecting the driving means of other of the plungers with its particular source of power. A still further and more particular object is to provide means operable on the movement of the plunger driving means for connecting the other plunger driving means with a source of power and disconnecting the first '15 named plunger driving means from a source of power.

The invention consists in other featuresand advantages which will appear from the following description and upon examination of the drawings. Structures containing the invention may partake of different forms and still embody the invention. To illustrate a practical application of the invention, we have selected a sheet metal press as an example of the various structures 5 and details thereof that contain the invention and shall describe the selected sheet metal press hereinafter, it being understood that variations may be made without departing from the spirit of the invention. The particular sheet metal press selected is shown in the accompanying drawings and described hereinafter.

Fig. 1 of the accompanying drawings illustrates a front of the sheet metal press selected as illustrative of structures containing the invention. Fig. 2 illustrates a vertical longitudinal section of the press shown in Fig. 1. Fig. 3 illustrates an enlarged perspective view of the actuating mechanism for controlling the operation of the blank holder and upper plunger of the press. Fig. 4 co illustrates a view in perspective of the actuating mechanism for controlling the operation of the lower or third plunger of the press. Fig. 5 illustrates diagrammatically an electrical circuit through which the mechanism of Figs. 3 and 4 (5 function. Fig. 6 illustrates diagrammatically one of the composite movements of the blank holder and plungers relative to the degrees of rotation of the several machine drive shafts obtainable by the use of our invention.

The frame of the sheet metal press shown in the drawings for purposes of illustration and application of our invention has a base I, a crown 2, and uprights 3 located between the base and the crown. The crown 2 and base I are suitably as far) fixed in assembled relation by the usual tie rods 4 which extend through the uprights 3. The base I has a bed portion 5 on which suitable shaping dies may be locked and on which the sheet metal to be worked on may be placed. The crown has suitable bearings in which to support a machine drive shaft 6 for driving a blank holding plunger 8 and shaping plunger I0.

The blank holding plunger 8 is slidably supported in ways 9 on the uprights 3 and is connected to the machine drive shaft 6 so that during successive rotation of the shaft the blank holding plunger approaches the bed 5 and then dwells for a prolonged period of time during the continued rotation of the machine drive shaft. As illustrated in the drawings, the machine drive shaft has end cranks I2 to the ends of each of which are pi otally connected a reciprocating pitman I4. Each reciprocating pitman is connected to a rocker lever I5 pivotally mounted, as at I6, on the crown of the press. Each rocker lever I5 is pivotally connected as by a link IT to a bellcrank I8 pivotally mounted, as at I9, in the crown of the press. Each bell-crank I8 is pivotally connected as by a link 20 to an arm 2I of a rock shaft 22. Each rock shaft 22 is rotatably mounted in spaced parallelism to each other in the crown of the press and has end arms 24. The end arms 24 of each rook shaft 22 are pivotally connected by links 25 to two corner portions of the blank holder. Each arm 24 and associated link 25 forms in their relation to each other toggle links for moving the blank holder and causing it to perform a prolonged dwell during normally continued rotation of the shaft 6 through certain degrees.

The machine drive shaft 6 may have eccentric or crank connections for connecting the shaping plunger I therewith. In the construction shown in the drawings, the machine drive shaft 6 has a pair of cranks 26 to each of which are connected pitmen 21. The end of each pitman 21 is connected to the shaping plunger I0 so that upon continued rotation of the machine drive shaft the plunger to will describe a continued reciprocation relative to the bed of the press. The cranks 26 are so angularly disposed-on the shaft 6 relative to the cranks I2 that the blank holding plunger 8 approaches the bed 5 of the press in advance of the approach of the shaping plunger I6. Thus it will be seen that sheet metal disposed on the bed will be engaged by the blankholding plunger 8 and held in position thereby during the dwell period described by the blank holder and during the shaping action of the plunger Ill. The plungers 8 and I0 may be provided with suitable adjusting means for adjusting the plungers relative to their actuating elements and to maintain them in desired sheet metal engaging relation. Pneumatic or hydraulic loading means may be provided for taking up play between the points of connections of the plungers with their actuating means in a manner well known in the art.

Slidably disposed inways 28 below the bed 5 is a third plunger 38 which may, according to the dies carried thereby, constitute a shaping plunger I and cooperate in sheet metal shaping function with the plungers 8 and I0. The plunger 30 is reciprocated by means of a machine drive shaft 3|. The shaft 3| may be-rotatably supported in bearing portions formed in the base I of the press. The shaft 3| may be connected to the plunger 30 by suitable eccentric or crank connections. As shown in the drawings, the shaft 3| has a pair of crank arms 33 to each of which is pivotally connected a pitman 34. The end of each pitman is suitably connected to the plunger 30 so that upon continued rotation of the shaft 3|, the

plunger will be reciprocated relative to the bed 6 driven from an independent source of power through suitable power transmission or coupling means. Thus, the drive shaft 6 is driven by a suitable motor 48 which is belted to a fly wheel 4| of a power transmission means. The power transmission means is preferably of a form and construction described in our application Serial No. 703,192 filed December 20, 1933 wherein a clutch and brake control device is described. The clutch and brake control device 39 has means for operatively connecting the fly wheel 4| with a driven pinion shaft 43 in response to the application of a pneumatic medium to establish clutching and for operatively connecting the pinion shaft 43 to elements resistant to movement upon failure or withdrawal of said pneumatic medium to brake the movement of the shaft. Other brake and clutch combinations may be used with like effect. A pinion 44 may be suitably keyed to the shaft 43 and disposed in meshing relation with a gear wheel 45. The gear wheel 45 is keyed to a countershaft 46 suitably journaled in the crown 2 of the press. At each end of the shaft 46 is keyed a pinion 48 which meshes with the teeth of a bull wheel 38 mounted on each end of the shaft 6 and keyed thereto. Thus, the machine drive shaft 6 may be driven or .be held against rotation in direct relation to the application of a pneumatic actuating medium to the clutch and brake control device 39.

A pneumatic actuating medium may be applied to clutch and brake control device 39 from a suitable source through a conduit or pipe, illustrated diagrammatically at 49 in Fig. 5. The pipe 49 has a valve 50, the valve member of which is operated by an arm 5|. The arm 5| is operatively connected to the movable core 52 of a solenoid coil 53 which normally holds the arm 5| in a valve closed position. The solenoid 53 may be enert0 gized by a current from a suitable source carried by main line conductors LI and L-2 and controlled by means disposed in the circuit therewith to open the valve.

The solenoid coil 53 circuitcomprises a fixed contact 55 of a suitable relay switch 56, line 54, solenoid coil 53, and line 5! and to a fixed contact 58. The relay switch 56 is magnetically operated by a coil 60, the circuit of which comprises mainline L-|, line 65, contact 64 of switch 60 63 normally held closed, contact 62, line 6|, coil 66, line 61, line 68, line 69, contact III of the starting switch II, adapted, on starting, to be closed by depressing, contact I2, line 13, line I4, fixed contact 15 of the rotary selector switch 16, (:5 arm I1 and arm I8 of switch I6, fixed contact I9, line 88, line 8|, line 82 to main line L--2. Thus, it will be seen that when switch II is depressed, the coil 6|) will be energized to actuate the relay switch 56 and connect the circuit of the solenoid coil 53 through the switch movable contacts and fixed contacts 83 and 84 of the relay with the main lines L-2 and L-I, respectively. The solenoid coil 53 will thus be energized to magnetically actuate the core 52 to open the valve 50 and thereby apply a pneumatic actuating medium tothe clutch and brake control device 39 operatively connecting the shaft 6 with the driving motor 49 and starting the rotation of the shaft with resultant advancement of the plungers 8 and I9.

A holding circuit for the relay 56 is provided so that upon release of the switch II, the above described circuit relationwill be maintained for a predetermined period. The relay holding circuit comprises main line L-I, line 65, contact 64, switch 63,-contact 62, line 6|, coil 69, fixed contact 85, movable contact 86, fixed contact 81 of relay 56, line 88, fixed contact 89, movable contact 99 of a switch 9|, line 92, contact 93, arm 94, of

selector 16, arm 18, line 39, line 8|, line 82, to

main line L2. The relay holding circuit thus established is controlled by switch 9| normally held closed.

The movable contact 99 is moved in response to a predetermined movement of the plungers 8, I9, and 39 of the press and, as is apparent from the foregoing description, in being moved to break the circuit of the relay 56 results in closing of the valve 59 and the operative disconnection of the shaft 6 with the motor 49. In the form shown in the drawings, the movable contact 99 of the switch 9| is operated by an arm 95 having a roller 96 mounted on the end thereof. The roller 96 is adapted to ride on the face of a cam member 91. The cam member may have peripheral high points 98 at which the roller 96 will be displaced sufiicient to cause a break in the circuit controlled by the switch 9|. The cam member 91 may be locked on the shaft 6 and rotate therewith, thus causing periodic movement of the arm 95 and its switch 9| with a resulting regulated interruption of the holding circuit of the relay 56 controlling the valve 59 of the clutch and brake control connected to the shaft 6.

By varying the location of the peripheral points 98 and decreasing or increasing the number on the cam 91, variations of sequence of movement of the plungers 8 and I9 may be obtained. In the motion diagram illustrated in Fig. 6 of the drawings, the line I99 represents the movement of the blank holding plunger 8 in relation to the degrees of rotation of the shaft 6 and the line |9I represents the movement of the plunger I9 under like conditions. The high points 98 of the cam 91 are disposed so that disengagement of the shaft 6 from the motor 49 will be automatically effected after the completion of a 189 degree movement of the shaft. On the diagram in Fig. 6, the shaft 6 has ceased to rotate at the point indicated as I 92. It will be observed that approximately a half of the normal dwell period of the blank holder 8 has elapsed and that the plunger I9 is substantially at a point in its maximum stroke. At this point in the operation of the press, means is provided for automatically initiating and operatively connecting the machine drive shaft 3| to its source of power to move the plunger 39 toward the bed 5 and the stationary or dwelling plungers 8 and I9.

The drive shaft 3| is driven by a second motor 42 belted to a fly wheel 29 of a second clutch and brake control device 41 similar in form and action to the device 39. The clutch and brake control device 41 drives a pinion 28 which meshes with a gear wheel 29 keyed on a countershaft 32. The shaft 32 is suitably journaled in the base I of the press. The shaft 32 has a pinion 36 keyed to each end thereof, said pinion being disposed in meshing relation with a bull wheel 31 keyed to each end of the shaft 3|.

The pneumatic actuating medium for the control device 41 may be applied from a suitable source through a conduit or pipe I95, illustrated 5 diagrammatically in Fig. 5. The pipe I95 has a valve I96, the valve member of which is operated by an arm I 91. The arm |91 is operatively connected to a movable core I98 of a solenoid coil I99 which normally holds the arm I91 in a valve 10 closed position. The solenoid coll I99 may be energized through circuits established just prior to the above described stopping of the shaft 6 and the plungers 8 and I9 connected thereto.

The circuit of the solenoid coil I99 comprises a fixed contact I I9 of a relay switch I I2, line I I4, coil I99, line 5 and fixed contact II6 of the switch II 2. The fixed contacts H9 and H6 of the relay II2 are connectible with the main line source when the relay H2 is moved into circuit closing position.

The relay I I2 ,is moved into circuit closing position by a circuit comprising line LI, line 65, contacts 64,63, and 62, line 6|, line II1, coil II8 of the relay II2, line II9, fixed contact I29, movable contact I2I of switch I23, line I 22, line I24, line 14, fixed contact 15, arms 11 and 18 of selector 16, fixed contact 19, line 89, line BI and line 82 to line L--2. Thus, the coil I I8 will be energized to close the relay II2. It will be observed that the establishment of the foregoing circuit is dependent, while the relay 56 is closed, on the closure of the switch I23 which is normally held open. The closure of the switch I23 is effected just prior to the opening of the switch 9|.

In order to effect closure of the switch I23, a second cam member I25 is supported on and rotatable with the shaft 6. A roller I26 is adapted to ride the peripheral surface of the cam I25. The roller I26 is rotatably mounted on an arm I21 of the switch I23. The arm I21 is operatively connected to the movable contact I2I. The cam I25 has a peripheral high point I29 which on rotation of the shaft 6 causes periodic displacement of the roller I26 and closure of the switch I23. Upon closure of the relay II2, the contact |I9 will be connected by movable contact I39 of the relay III! to line I3I, and main line L-I and the contact II6 will be connected by movable contact I33 of the relay to a fixed contact I32 and line 82 to main line L-2 to energize the solenoid coil I99 and open the valve I96.

A maintaining circuit for the coil II8 of the relay I I2 is provided whereby the relay continues in circuit closed position despite the open position of the switch I23 and subsequent opening of the relay 56. The holding circuit of the coil II8 comprises line L-I, line 65, contacts 64, 63, and 62, line 6|, line |I1, coil II8, contact I35, contact I31, contact I38, all of the relay II2, line I39, fixed contact I49, movable contact I4I of the switch I42, line I43, line 92, fixed contact 93, arms 94 and 18 of selector 16, fixed contact 19, lines 89, 8|, and 82 to main line L-2. The continued maintenance of this circuit after estab- 85 lishment is dependent on the continued closure of the switch I42 which is normally held closed.

The movable contact I4I of the switch I42 is operatively connected to an arm I44 having a roller I45 rotatably mounted at one end thereof. The roller I45 is adapted to ride the face of a peripheral cam I46 mounted on and rotatable with the shaft 3|. The cam I46 has a high point I41 which when engaged by the roller I45 causes opening of the switch I42 with a resultant open- 15 ing of the relay 2 and closure of the valve I06 to disconnect the shaft 3| from its motor.- As indicated by the diagram in Fig. 6 of the draw ings wherein the line I49 indicates the movement described by plunger 30 relative to the movements of the plungers 8 and I0 and the degrees of rotation of the shaft 3|, the switch' I23 is operated at the points I41, and the switch I42 is operated at the points I48, the curved portion of the line intermediate the points indicating the approach and recession of the plunger 30 and the straight portion of the line in alternating relation to the curved portion representing the rest or dwell periods of the plunger 30. Variations of performance of the plunger 30 may be obtained by variation of the cams I25 and I46.

In order to retract the plungers 8 and I0 in synchrony with the recession of the lower plunger after completion of the draw and redraw of the sheet metal, means are provided for again closing the relay 56 with a resultant opening of the valve 50, the said means being initiated by the rotation of the shaft 3i.

A second cam I is mounted on and rotatable with the shaft 3 I. The cam I50 has a peripheral high point I5l on its peripheral face which is adapted to be ridden by a roller I52. The roller I52 is mounted on an arm I53 which is operatively connected to a movable contact I55 of a switch I56. The contact I55 is normally held in open position relative to a fixed contact I58 and when closed by the combined action of the roller I52 and cam I50 closes a circuit which closes the relay 56. The circuit controlled by the switch I56 comprises main line L-I, line 65,

, contacts 64, 63, and 62, line 6i, coil 60, line 61,

line I66, contacts I58 and I55 of switch I56, line I6I, line I24, line 14, contact 15, arms 11 and 18, contact 19, lines 80, BI, and 82 to main line L--2. Thus, on closure of the switch I56, the coil 60 is energized to close relay 56 and open valve 50 as heretofore described resulting in the continued rotation of the-shaft 6 and recession of the plungers 8 and I0. As indicated in Fig. 6, the switch I56 is operated at the point I on the line I00 to again start the shaft 6. It will be observed that the plunger I0 begins to at once recede, while the blank holding plunger 8 comp'etes its natural uncompleted dwell period, whereupon it likewise recedes until the switch 9i is actuated by the cam 91 to open. The plungers 8, I6, and 30 are thus stopped, each at a fully retracted point in their natural stroke. Successive operations may be again effected by depressing the starting button II. Variations of dwell periods of the plungers 8 and I0 relative to movement of the plunger 30 may be obtained by varying the cam 91. I

It will be noted that in all the described control circuits of the circuits actuating either of the valves 50 or I06 include the contacts 62, 63,

and 64. Thus, by depressing the movable contact 63, the plungers may all be immediately stopped at any point in their above described cycle of movement. I

If desired, the selector 16 may be rotated so as to cut out of circuit the holding circuits for the relays 56 and H2 and cut in to circuit the switches I10 and HI which may be utilized to cause rotation of the shafts 6 and 3I for only so long as the switches I10 and "I are maintained closed. The switches I10 and HI are of great use when it is desired to advance the plungers by steps. The selector 16 may be rotated so that the arm 94 contacts with contact I12 and arm 18 contacts with contact I14. The switch I10 controls a circuit comprising main line L--I, line 65, contacts 64, 63, and 62, line 6|, coil 60,.lines 61 and 68, line I16, switch I10, line I19, contact I12, arms 94 and 18, contact I14, line I11, lines 8| and 82 to main line L--2. Closure of the switch I10 will cause closure of the relay 56 with a resultant opening of the valve 50 and rotation of the shaft 6. This described circuit will not be sustained upon opening of the switch I10.

The switch I1I controls a circuit comprising main line Ll, line 65, contacts 64, 63, and 62, line 6l,line II1, coil H0, line I80, switch I", line I8l, line I19, contact I12, arms 94 and 18, contact I14, lines I11, 8i, and 82, to main line L-2. Closure of the switch "I will cause clo sure of the relay II2 with a resulting opening of the valve I06 and rotation of the shaft 3|.

A hand operated switch I85 may be provided in line I I4 which, when open, cuts out the circuit of the coil I09 notwithstanding closure of the relay H2. Thus, the valve I06 will not be operated, and the plunger 30 will be maintained stationary to convert the triple action press into a double action type.

We claim:

1. A sheet metal press having a pair of rotatable machine drive shafts, a pair of movable plungers, each plunger operably connected to a machine drive shaft, a source of power, a controllably operable mechanism for connecting each machine drive shaft to the source of power, actuating means for each of said mechanisms operatively connecting each machine drive shaft and the respective mechanism of the other shaft for actuating the same upon a predetermined rotation of the former shaft.

2. A sheet metal press having a crown and a base, a pair of machine drive shafts, one of said machine drive shafts rotatably supported in the crown and the other of the machine drive shafts rotatably supported in the base, a pair of plungers,

.one of the said plungers connected to and operated by the drive shaft in the crown and the other of the plungers connected to and operated by the drive shaft in the base, a driving member associated with each drive shaft, a clutch mechanism for connecting each drive shaft with its associated driving member, a clutch operating means connected to each drive shaft for connecting the other drive shaft with its associated driving member and disconnecting the driving member from its associated drive shaft to which the said means is connected.

3. A sheet metal press having a crown and a base, a. pair of machine drive shafts, one of said machine drive shafts-rotatably supported in the crown and the other of the machine drive shafts rotatably supported in the base, a pair of plungers, one of the said plungers connected to and operated by the drive shaft in the crown and the other of the plungers connected to and operated by the drive shaft in the base, a driving member associated with each drive shaft, a clutch mechanism for connecting each drive shaft with its associated driving member, a clutch operating means adjustably connected to each drive shaft for connecting the other drive shaft with itsassociated driving member, and a second clutch operating means adjustably connected to each drive shaft for disconnecting the driving member associated with the drive shaft to which the said second clutch operating means is connected for producing dwells in the movement of its plunger and the same time periods of complete rotation of each drive shaft.

4. A sheet metal press having a crown and a base, a pair of machine drive shafts, one of said machine 'drive shafts rotatably supported in the crown and the other of the machine drive shafts rotatably supported in the base, a. pair of plungers, one of the said plungers connected to and operated by one 01 the drive shafts and the other of the plungers connected to the other of the drive shafts, a clutch mechanism for operatively connecting each drive shaft with its associated driving member, a clutch operating means operatively connected to each drive shaft for disconnecting the drive shaft from its associated driving mem-- her, and a second clutch operating means adjustably connected to each drive shaft for connecting the other drive shaft with its associated driving member subsequent to its disconnection by the first named clutch operating means to produce dwells in each of the plungers during the operation of the other of the plungers.

5. A sheet metal press having a crown and a base, a pair of machine drive shafts, one of the said machine, drive shafts rotatably supported in the crown and the other of the machine drive shafts rotatably supported in the base, a pair of plungers connected to the drive shaft rotatably supported in the crown, one of the plungers connected to the said drive shaft by a plurality of sets of mechanical elements, each set having a plurality of toggles for producing an extended dwell in the movement of the last named plunger, a third plunger connected to and operated by the drive shaft in the base, a driving member associated with each drive shaft, a clutch mechanism for operatively connecting each drive shaft with its associated-driving member, a clutch operating means adjustably connected to each drive shaft for connecting the other drive shaft with its associated driving member and disconnecting the driving member associated with the drive shaft to which the said means is connected.

6. A sheet metal press having a crown and a base, a pair of machine drive shafts, one of the said machine drive shafts rotatably supported in the crown and the other of the machine drive shafts rotatably supported in the base, a pair of plungers connected to the drive shaft rotatably supported in the crown, one of. the plungers connected to the said drive shaft by a plurality of,

toggles for producing an extended dwell in the movement of the last named plunger, a third plunger connected to and operated by the-drive shaft in the base, a driving member associated with each drive shaft, a clutch mechanism for operatively connecting each drive shaft with its associated driving member, a clutch operating means adjustably connected to each drive shaft for disconnecting the drive shaft from its asso- 5 ciated-driving member, a second clutch operating means adjustably connected to each drive shaft for connecting the other drive shaft with its associated driving member subsequent to the disconnection produced by the first named clutch 10 operating means to cause cessation of rotation of one drive shaft during the operation of the other drive shaft and to produce a complete rotation of. each drive shaft in the same time period.

'7. A sheet metal press having a pair of rotat- 15 able, machine drivelshafts, a pair of movable plungers, each plunger operably connected to a machine drive shaft, 9. source of power, a mechanism associated with each drive shaft for operably connecting the same to. the source 01-20 power, actuating means operably connected to each shaft for. actuating the mechanism associated with the other shaft to connect the same with the source'of power, and a second actuating means operably connected to each shaft for ac- 25 tuating the mechanism associated therewith to disconnect the said shaft fromthe source of power at the end of each complete rotation of the same. t

8. A sheet metal press having a pair of rotatable machine drive shafts, a pair of movable plungers, each plunger operably connected to a machine drive shaft, a source of power, a mechanism associated with each drive' shaft for operably connecting the same to the source of 35 power, actuating means operably connected to each shaft for actuating the mechanism associated with the other shaft to connect the same with the source of power at a predetermined point in complete rotation of the said one shaft, and a sec-4o 0nd actuating meansoperably connected to each shaft for actuating the mechanism-associated therewith to disconnect the said shaft from the source of power at the end of each complete rotation of the same.

9. A sheet metal press havinga pair of rotatable machine drive shafts, a pair of movable predetermined rotation of the said other shaft.

FREDRICH' 'J. RODE. MEREDITH .R. HATCH. 

